1. Field of the Invention
The present invention relates to fluid pumps assemblies and, more particularly, to modular pump assemblies having a fluid pump and a fluid activated motor for driving the fluid pump.
2. Description of Related Art
Various fluid pump systems have been developed which have one or two pump assemblies driven by a fluid activated motor such as an air motor. Some of these pump systems are produced in a modular design that accommodates manufacture of pump assemblies that provide different pumping performance parameters such as, for example, different pumping pressures, different volumes, or different flow rates. These modular designs, however, may not facilitate rapid assembly and disassembly of the pump system for interchanging pump assemblies, inspection, repair, or replacement of parts with little downtime or loss of production. Additionally, these modular designs may not allow pump assemblies having a relatively wide range of performance parameters to be used with a common air motor.
The air motor typically uses compressed air during a portion of the pumping cycle and exhausts the compressed air to atmospheric pressure. This rapid expansion of the compressed air to atmospheric pressure can be very noisy. Therefore, some air driven pumps have utilized various types of external mufflers to reduce the amount of noise caused by the exhausted air. These external mufflers, however, add to the overall complexity of the pumps by adding additional parts which can contribute to greater manufacturing costs and/or greater repair downtime for the pumps.
Additionally, if the air contains moisture or water vapor which is not removed before the air enters the pump, the cooling effect of polytropic adiabatic expansion of the air as the air is exhausted from the pump can cause the water vapor to freeze. The moisture tends to build up in and block the exhaust passage when it freezes and can eventually completely shut off the exhaust passage and prevent operation of the pump. Therefore, some air driven pumps have utilized various types of air mixing or moving elements to reduce the amount of ice formation caused by the exhausted air. These types of ice reducing mechanisms, however, add to the overall complexity of the pumps by adding additional parts and/or flow paths which can contribute to greater manufacturing costs and/or greater repair downtime for the pumps.
Accordingly, there is a need for an improved fluid driven pump which has a rapidly assembled and disassembled modular design for ease of maintenance and interchangability and which has a common air motor for driving pump assemblies having a relatively wide range of performance parameters. Additionally, there is a need for an improved fluid driven pump which is relatively easy to manufacture and maintain, which provides noise reduction in a relatively simple manner, and which provides reduced blockage due to freezing exhaust, in a relatively simple manner.